--- title: "Money and How Banks Create It" description: "Money is whatever does three jobs at once: settles a payment, stores value until later, and gives prices a common scale. Banks hold deposits and lend most of them out, and because each loan becomes so" canonical: https://lightmysky.com/learn/civics-and-economics/money-and-how-banks-create-it-mt_ytmJOgw66I source: https://lightmysky.com/learn/civics-and-economics/money-and-how-banks-create-it-mt_ytmJOgw66I.md retrieved: 2026-09-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Money and How Banks Create It Money is whatever does three jobs at once: settles a payment, stores value until later, and gives prices a common scale. Banks hold deposits and lend most of them out, and because each loan becomes somebody else's deposit, lending itself enlarges the quantity of money in circulation. Subject: Civics & Economics · Area: Economics · Ages 15 to 16 Page: https://lightmysky.com/learn/civics-and-economics/money-and-how-banks-create-it-mt_ytmJOgw66I ## Ready when they can - Name the three functions of money and test an awkward candidate against them (gold, air miles, a crypto coin) - Trace a deposit through a bank's lending and show why the total amount of money grows - Explain what a reserve is for and why a rush of withdrawals threatens a bank that is not insolvent ## Lesson: What money is and how banks multiply it Money is whatever people accept as payment, from shells to notes to numbers on a screen. It does three jobs at once: a medium of exchange so you need not barter, a unit of account so prices make sense, and a store of value so savings keep. Test any candidate against all three. Gold buys coffee awkwardly, air miles fail outside one airline, and volatile crypto coins wobble as a store of value. **Example.** Banks are matchmakers between savers and borrowers. They gather deposits, keep a slice in reserve, and lend the rest to home buyers and firms. Borrowers pay interest, savers earn a smaller rate, and the bank lives on the spread while judging who repays. By pooling thousands of deposits, banks turn short-term savings into the long-term loans the economy needs. Banks do not just move money, they multiply it. Take a 100 coin deposit with a 10 percent reserve rule: the bank keeps 10 and lends 90, which lands in another bank as a new deposit. That bank keeps 9, lends 81, and the chain rolls on, each round smaller than the last. Add up every deposit and the total far exceeds the first 100 coins. The reserve ratio sets the limit. **Tip.** A bank lends long and borrows short, which makes it fragile by design. Most deposits are tied up in loans, so if every saver queues at once, even a healthy bank runs dry: that panic is a bank run. Reserves cushion small shocks, deposit insurance calms savers, and central banks can lend in a crisis. Rules exist because one falling bank can scare the whole street. **Recap.** Money passes three tests at once, and lending turns one deposit into many. ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Money, Banking and Interest Rates](https://lightmysky.com/learn/civics-and-economics/money-banking-and-interest-rates-mt__aqBHw2wZM) ## Opens up - [Monetary Policy and What a Central Bank Can Do](https://lightmysky.com/learn/civics-and-economics/monetary-policy-and-what-a-central-bank-can-do-mt_w0xvI0iouQ) - [Interest, Compound Growth and the Cost of Borrowing](https://lightmysky.com/learn/civics-and-economics/interest-compound-growth-and-the-cost-of-borrowing-mt_Zzl9SWMgvQ)